Zellio.io

Barcode Generator

Create Code 128 barcodes from any text or number — download as PNG or SVG.

Runs locallyWorks offlineShare link carries settings, never your data
Send output toQR Code GeneratorPassword GeneratorFocus TimerBuild a workflow from thisOutput stays on this page until you send it.

Frequently asked questions

What is Code 128?

Code 128 is a high-density linear barcode that can encode all ASCII characters, making it ideal for shipping, logistics and inventory labels. Unlike simpler barcodes like Code 39, Code 128 encodes the full ASCII character set (letters, numbers, and symbols), so you can embed shipping addresses, product descriptions, or other text directly into a barcode. The high density packs information into a small space, making Code 128 compact enough for small package labels or detailed inventory tags. Code 128 is the standard for UPS, FedEx, and DHL shipping labels worldwide.

PNG or SVG for printing?

Use SVG for printing and labels because it stays sharp at any size; PNG is fine for quick on-screen use. SVG (vector graphics) scale perfectly to any resolution without quality loss, so barcodes generated at 10×10 mm scale identically to 100×100 mm with perfect sharpness. PNG (raster graphics) becomes pixelated or blurry if enlarged significantly, limiting usability for large format printing. For professional shipping labels, product packaging, or any printed barcode, SVG is the better choice; PNG is acceptable for temporary on-screen barcodes or quick internal use.

Is my data uploaded?

No. Everything runs locally in your browser using standard web APIs — your text, files and inputs are never uploaded to a server, so the tool works even offline once the page has loaded.

Pro tips

  • Export SVG for anything going to print. A scaled-up PNG softens the bar edges that scanners depend on.
  • Leave clear margin either side of the symbol — a barcode with no quiet zone is the single most common cause of a no-read.
  • Scan the actual printed label, not the screen preview. Paper, ink spread and lamination all change how a symbol reads.
  • Keep encoded values short. Every extra character makes the symbol denser, and density is what pushes a barcode past what a cheap scanner can resolve.
  • Avoid printing on curved or reflective surfaces where you can; both distort the bar widths the scanner is measuring.

About Barcode Generator

Encodes Code 128 subset B, which spans the printable ASCII range — letters, digits, punctuation and spaces. Export SVG for anything going to print, since a scaled-up PNG loses the crisp edges scanners depend on.

Generate a scannable Code 128 barcode from any text or number and export it as a crisp PNG or vector SVG. Code 128 is a compact, high-density format widely used for shipping labels, inventory, asset tags and product tracking.

Type a value, preview the barcode and download it ready for printing. Scan the preview with a phone before committing to a print run — a symbol that is too small or too low-contrast fails at the scanner, not on screen.

Code 128 suits internal identifiers precisely because you choose the value. Retail symbologies do not work that way: EAN-13 and UPC-A encode a registered product number, and the final digit is a check digit computed from the others, so an invented number is rejected by any scanner that validates it. If you need a barcode for a product sold through retail, the number has to come from GS1 rather than from you.

Printing is where most barcodes fail, and quiet zones are the usual reason. A symbol needs clear space either side — roughly ten times the width of its narrowest bar — for a scanner to find its edges, so a barcode butted against a label border or a fold often will not read. Contrast matters just as much: scanners want dark bars on a light background, and a coloured or glossy substrate can defeat one that looked fine on screen.

Common use cases

  • Small businesses labelling inventory or stock locations with their own internal reference numbers.
  • IT teams tagging laptops and equipment so an audit can be done with a handheld scanner instead of a clipboard.
  • Libraries, clubs and community groups producing membership or loan cards.
  • Event organisers generating scannable ticket or attendee references.
  • Warehouses labelling shelves and bins so picking can be confirmed by scan rather than by eye.
How it comparesFull label software such as BarTender or NiceLabel handles templates, databases and print runs, which is what a warehouse needs and considerable overhead for twenty asset tags. This produces the symbol itself; the layout is left to whatever you already use for printing.